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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

27348 results found.

  1. GRB 260516D: GROWTH-India Telescope optical counterpart discovery
  2. GRB 260516D: SVOM/VT optical bright candidate
  3. GRB 260515A: CrAO ZTSh BVRI optical observations
  4. Fermi GRB 260516C: Global MASTER-Net observations report
  5. SVOM GRB260516.86: Global MASTER-Net observations report
  6. GRB 260516D: SVOM possible detection of a short faint burst
  7. GRB 260515A: LCO optical counterpart detection
  8. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) further optical observations
  9. EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  10. EP260514a: NOT optical counterpart confirmation
  11. EP260514a: TRT optical counterpart candidate
  12. EP260514a: SVOM/VT optical candidate
  13. Fermi GRB 260516B: Global MASTER-Net observations report
  14. GRB 260515A: OHP/T193 optical observations
  15. EP260514a: COLIBRÍ optical upper limits
  16. GRB 260515A: LCO optical observations
  17. SVOM GRB 260515A: Global MASTER-Net observations report
  18. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  19. GRB 260515A: SVOM/VT optical candidate from VHF data
  20. GRB 260515A: JinShan optical counterpart candidate
  21. GRB 260515A: SVOM detection of a burst
  22. GRB 260510C: Glowbug gamma-ray detection
  23. EP260514a: GROWTH-India Telescope optical upper limit
  24. GRB 260511B: GMG Optical Upper Limit
  25. EP260514a: Global MASTER-Net observations report
  26. EP260514a: Einstein Probe detection of a fast X-ray transient
  27. EP260512a: LCO optical upper limits
  28. GRB 260511B: Mephisto multi-band optical followup
  29. Fermi GRB 260514A: Global MASTER-Net observations report
  30. GRB 260512A: AstroSat CZTI detection
  31. EP260512a: EP-FXT follow-up observation
  32. EP260507a: Xinglong Schmidt optical counterpart detection
  33. EP260512a: Global MASTER-Net observations report
  34. Fermi GRB 260513A: Global MASTER-Net observations report
  35. Fermi GRB 260512A: Global MASTER-Net observations report
  36. GRB 260511B: further SAO RAS optical observations
  37. GRB 260509A: SVOM/VT optical observations
  38. The EP-WXT trigger 01709262036 is likely a flaring star
  39. EP260512a: COLIBRÍ optical upper limits
  40. EP260512a: Einstein Probe detection of an X-ray transient
  41. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  42. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  43. GRB 260512A: NuSTAR detection of prompt emission
  44. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  45. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  46. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  47. GRB 260511A: Glowbug gamma-ray detection
  48. GRB 260511B: SAO RAS optical observations
  49. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  50. GRB 260511B: FRAM-ORM optical detection
  51. GRB 260511A: EP-FXT follow-up observation
  52. GRB 260511B: EP-FXT follow-up observation
  53. GRB 260511B: LCO optical counterpart detection
  54. GRB260511B: MAO/AZT-22 optical observations
  55. GRB 260511B: LCO optical observations
  56. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  57. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  58. GRB 260510B: EP-FXT follow-up observation
  59. GRB 260510C: Fermi GBM Observation
  60. GRB 260509A: SAO RAS optical observations
  61. GRB 260511A: REM near-infrared detection
  62. GRB 260511B: GROWTH-India Telescope optical observations
  63. GRB 260506B: Glowbug gamma-ray detection
  64. GRB 260506A: Glowbug gamma-ray detection of a short burst
  65. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  66. GRB 260511B: NuSTAR detection of prompt emission
  67. GRB 260511A: NuSTAR detection of prompt emission
  68. GRB 260511B: Fermi GBM Detection
  69. GRB 260511B: SVOM/VT optical observation with VHF data
  70. GRB 260511B: TRT optical observation
  71. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  72. GRB 260511A: Fermi GBM Detection
  73. GRB 260511B SVOM/C-GFT optical counterpart detection
  74. EP260509a: LCO optical upper limits
  75. GRB 260511A: UTGO H50 optical afterglow observation
  76. GRB 260511B: SVOM detection of a burst
  77. GRB 260510C: EP-FXT follow-up observation
  78. EP260509a: EP-FXT non-detection and upper limit
  79. GRB 260511A: SVOM/VT optical observation with VHF data
  80. Fermi GRB 260511A: Global MASTER-Net observations report
  81. GRB 260511A: KAIT optical afterglow observations
  82. GRB 260511A: LCO optical afterglow detection
  83. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  84. GRB 260511A: TRT optical counterpart detection
  85. GRB 260511A: SVOM detection of a bright burst
  86. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  87. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  88. GRB 260510C: MAXI/GSC detection
  89. EP260509a: Global MASTER-Net observations report
  90. Fermi GBM Sub-Threshold Detection of GRB 260510B
  91. GRB 260510C: SVOM detection of a burst
  92. GRB 260510B: LCO optical upper limits
  93. EP260509a: Einstein Probe detection of an X-ray transient
  94. GRB 260509A: Liverpool Telescope optical observations
  95. GRB 260510B: SVOM detection of a burst
  96. GRB 260509A: LCO optical observations
  97. SVOM GRB 260509A: MASTER-OAFA optical observation
  98. Fermi GRB 260510A: Global MASTER-Net observations report
  99. GRB 260509A: KAIT optical observations
  100. GRB 260509A: SVOM/COLIBRÍ (FM-GFT) observations

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